Calculating machine



CALCULATING MACHINE Filed Dec. 23, 1937 16 Sheets-Sheet 1 H. K. F. EWALD ErAL May 27, 1941.

[lf-Kim Ao/-wey May 27, 1941 H. K. F. EwALD ErAL 2,243,150

CALCULAT ING MACHINE Filed Deo. 25, 1957 16 Sheets-Sheet 2 Hg. 7a

May 27, 1941- H. K. F. x-:wALD ErAL 2,243,150

CALGULATING MACHINE Filed Dec. 23, 195'?v 16 Sheets-Shee; 3

May 27, 1941. H. K. F. EWALD ETAL 2,243,150

CALCULAT ING MACHINE May 27, 1941. H. K. F. EwALD ETAL 2,243,150

CALCULATING MACHINE Filed Dec. 25, 1957- 1e shets-sheet s forney' H. K. F. EWALD ETAL 2,243,150

' CALCULATING MACHINE lMay 27, 1941.

Filed Dec. 25, 1937 16 Sheets-Sheet G ,m s r v o Y f. wa y e n a n n e wf, f 7 /v/ f A. V E P n O n A H. S A K ,M H. v/ B S c im 2t as EN S EN Ow l&\ www 5&1 5T WIN 22a n a. w m g mmm n S, f u a N M n R 2 N 2 u 2 Nv May 27 1941- H. K. F. EwALD ETAL 2,243,150

CALCULATING MACHINE Filed Deo.

23, 1937 16 Sheets-Sheet 7 O mmm.

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May 27, 1941- H.,K. F. EwALD ETAL 243,150

. CALCULATING MACHINE Filed Dec. 23, 1937 16\ Sheets-Sheet 8 "a 494 ya@ May 27, 19,41. n. K. F. EWALD HAL CALCULATING MACHINE Filed Dec. 23, 1937 y16 Sheets-Sheet 9- ffl/anfora. H/f/'EwaZJam h. E/'L By en? May 27 1941 H. K. F. EWALD ETAL 2,243,150

CALCULATING MACHINE Filed Deo. 23, 1957 16 Sheets-Sheet 10 d n. ,M 0 @Wh m w52. IE5 n KK.. o L

May 27, 1941. H. K. F. EWALD Erm.

CALCULATING MACHINE Filed Dec. 23, 1937 16 Sheets-Sheet l1 May 27, 1941.

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CALGULATING MACHINE Filed Dec. 23, 1957 16 Sheets-Sheet l2 May 27, 1941. H. K. F. l-:wALD :TAL 2,243,150

CALGULATING MACHINE Filed Dec. 25. 1937 16 Sheets-Sheet 13 all May 2,7, 1941. H. K. F. EwALD Erm. 2,243,150

CALCULATING MACHINE Filed Dec. 23, 1957 16 Sheets-Sheet 14 May 27,r 1941 H. K. F. EwALD ETAL 2,243,150

CALCULATING MACHINE 'Filed Dec. 23, 193k? 16 Sheets-Sheet 15 16 Sheets-Sheef 16 .\1. ,Kumi

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May 27, 1941. H. K. F. EwALD ETAL CALCULATING MACHINE Filed Dec. 23, 1937 machine operation.

Patented 'May 27,v 1941 comme moms nam-an am nuria. anla im um Karl Application December In Germany ZCIlims.

The present application is a continuation-inpart of applicant's application Serial No. 66,952, iiled March 3, 1936.

The present invention relates to a calculating machine in which correct positive totals can be taken when an adding subtracting totalizer conl tains a positive amount and is in addition position, and correct negative totals can be taken when the totalizer contains a negative amount and is in subtraction position, the flmitlve 1 be-Y ing automatically taken care oi'.

The object of the invention is to provide manually or automatically settable means for .conditioning thecalculating machine ior a totaltaking operation, by setting of which means an idle stroke of the machine is automatically initiated for shifting the totalizer from its adding position to its subtracting pomtion or vice 23, 1937, Serial March 8,

versa in such cases in which the content of the tota-lizer corresponds not with the position of the totalizer, immediately after the idle stroke the taking of the correct positive or negative total being automatically performed.

According to the invention this is achieved by means substantially comprising a setting means for total-taking whichis provided not only with means for connecting the'motor drive to shift the totalizer to position for the kind of calc`u1a.

tion corresponding to the character of the amount therein, but also with connections to control devices which are releasable at the end oi' the change-over operation oi' the machine, and by means of which connections the motor drive is automatically connected to clear the amount in the shifted totalizer, for afurther Mechanisnr'for a calculating machine embodying the present invention is illustrated by way of example in the accompanying drawings, in which: Figure 1 is a side'view of a` bookkeeping calculating machine, with the casing removed.

Fig. 1a is a top view partly in section of the right-hand elements of Fig. 1. Fig. 1b is a perspective view of the left-hand elements of Fig. 1.

Fig. 1c is a side elevation of the diierential mechanism for actuating the totalizer.

Fig. 1d is a side-elevationshowing the control armature with the total key d' s t Figs. 2 54 are side views illustrating a detail mechanism in dlierent operative positions.

Figs. 6 and 7 are partial side elevations in in which various control members, not shown in Fig. 1, are indicated.

Fig. 8 is a side view of a skip device for jumping over printing spaces.

Fig. 9 is a side view showing various motor keys with their corresponding operating connections.

Fig. 10 is a side view showing the for shifting the totalizer to addition or sub-l traction position.

Fig. 10a is a side view oi. a detail showing the connection of the shift member with the subtraction key according to Fig. 10.

Figs. 11 and l2 are end views of a detail showing the shift member for the subtraction slide according to Fig. 10 in two diiierent positions.

Figs. 13 and 14 are end views of a detail showing the subtraction slide according to Figs. 7 and 10 in diiierent positions.

Figs. 15 and 16 are end views of a detail showing the shift slide actuated by the subtraction slide, for the totalizer of Figs. 1, 7, i0 in diiferent positions.

Fig. 17 is a perspective partial view of the 'totalizer and shift mechanism seen from the rear.

Fig. 18 is a view similar to Fig. 17 of the totalizer and engaging means.

Fig. 19 isa perspective carrying mechanism.

Fligs. 20 and 21 are sections through the tens partial view o! the tens carrying mechanism taken on line 2li-20 of Fig.

19 and showing two diiferent positions.

Figs. 22, 23 and 24 are sections through the tens carrying mechanism taken on line 22-22 oi' Fig. 19 and showing three diierent positions.

Fig. 25 is a side view partly in section showing the mechanism for releasing the'paper carriage according to Fig. 9.

Fig. 26 is a side view partly in section showing the mechanism for testing the sign of the totalizer content.

Fig. 27 is a plan view of the mechanism oi' Fig. 26.

Fig. 28 is a section through the drive coupling though the machine may have a plurality of totalizers and 'a corresponding multiple of the operating parts hereinafter described. The machine shown in the 'drawings is of the full keyboard type with digit keys 450 which are held in depressed position, during the operation of the machine, by means of locking bars 45|, in the usual manner. By the depression of the digit keys 450 there is effected movement of zero levers 452 whereby these release their associated step bars 453.

Rack sectors 3 are connected by pins 650 to the step bars 453, Fig. 1c, which sectors are freely rotatable on a common shaft 65|. Each sector has an arm with teeth |14 engaging teeth |15 of rack bars |13. The rack bars are guided by means of pins 652, 653 engaging slots |16, |11 in the bars and are moved to and fro corresponding to the movement of the rack sectors 3. Accumulators, not shown, can be brought into engagement with the rack bars |13. Springs 654 attached to the rack sectors 3 urge the latter to rock in counter-clockwise direction. Type carriers I6 are jointed to the sectors 3, and by means of a bail 655 resting on the sectors 3, the latter are held in the position shown in Fig. 1c. The bail 655 is carried by a two-armed lever 656 pivoted about the shaft 65|, on the left-hand armof which lever is vmounted a roller 651 which cooperates with acam 658 fast on the main drive shaft The adding and subtracting totalizer 3|1 is mounted in a frame 156 supported in a second frame 660 having a rocker arm 151 which is shown in Fig. 1c. The frame 660 rocks about an axis 16| and the rocking of said frame causes the upper or the lower numeral wheel series of the totalizer 3|1 to come into and out of mesh with the rack sector teeth. as will be hereinafter described. The frame 660 is rocked by means of a disc 163 having a curved cam slot 162 co-operating with a stud 155 on the frame 660. The disc 163 is fast on a shaft164.

At the beginning of a machine operation the main drive shaft rotates counter-clockwise whereby the cam 658 releases the roller 651, Fig. 1c. Since in those ordinal places in which amount keys 450 are actuated the zero levers 452 have released the corresponding step bars 453, these bars can move to the left (Fig. 1c) under the pull of the springs 654 acting through the sectors 3, this msovement being limited by the stems of the depressed amount keys 450. Hereby the corresponding rack sectors are raised by amounts corresponding to the digits of the depressed keys and by means of hammers not shown, the set up digits are caused to be printed by the type carriers I6, at the platen roller I4.

At the 'beginning of the return stroke of the machine operation in which the main shaft moves contrary to the direction of the arrow |43, the totalizer 3|1 is brought into mesh with the rack sectors 3 and in the course of the return stroke the set up digit values are entered in the totalizer 3|1. The introduction of the digit values for addition and subtraction takes place in similar manner. according to Whether the upper or the lower series of numeral wheels of the totalizer, by means of a control device hereinafter described, engage the rack sectors 3.

Total-taking from the totalizer is prepared by means of total key 454 and sub-tota1 key 455.

The total key 454 and the sub-total key 455 cooperate at all times with a bell-crank 456 which is jointedly connected by a pin 451 to a push rod 458. At the right-hand end of the push rod 458 there is jointed a lever 460 pivoted at 459, which lever engages a pin 46| on a rod 462. The rod 462 is connected by a pin 463 with the lower arm of a bell-crank 464 pivoted at 654. At its left-hand end the rod 462 has a slot 466 in which engages a pin 461 on a lever 468. The lever 468 can rock on a pivot 469 and is drawn against the right-hand end of the slot 466 by means of a spring 410 attached to the rod 462. On depressing one of the total keys 454 or 455, the bell-crank 456 rocks in the clockwise direction and through the parts 458, 460 it pushes the rod 462 to the right, in Fig. 1. A pawl 412 pivoted on a pin 41| of the rod 462 is thereby carried to the right. This pawl 412 in this movement engages below a pin 413 on a lever 414 and thereby shifts a rod 415 which engages the motor drive to effect a machine operation, as will now be described. On the other end of the shaft 415 is attached a pawl 665 (Fig. urged in clockwise direction by a spring 661. In position of rest of the machine the pawl 665 is held by the spring 661 in engagement with a square pin 668 arranged on a rod 669 which, as shown in lFig. 31, is jointed at 610 to a lever 61| having several arms and pivoted about a shaft 612. To the lower arm of the lever 61| is attached a spring 613 which tends to turn the lever counter-clockwise. 'I'he left arm of the lever 61| carries a pin 614. On the shaft 612 is rotatably mounted a two armed lever 615 (Fig. 30) the left arm of which co-operates with a yoke 519 rotatable about a shaft 616. The right arm of the lever 615 has a lug 611 (Fig. 32) cooperating with a stop 618 on a yoke 619. The yoke 619 is rotatably mounted on a shaft 680. The yoke 619 has a lower arm 68| and an upper arm 682 the former of which arms has a pawl 684 pivoted on a pin 683 and urged in counter-clockwise direction by a spring 685, while the upper arm 682 is connected at 686 to a link 681 (Fig. 32) which link is jointedat 688 to a lever 690 (Figs. 30 and 31) pivoted about a pin 689 (Fig. 31). The The lever 690 has also jointed thereto a stop rod 692 (Fig. 29). This stop rod 692 extends into the casing 693 of the drive coupling. At the right end of the rod 692, Fig. 29, lies a pawl 694 which is mounted on the driven part of the coupling 695, Fig. 28. A spring 696 (Fig, 29) tends to turn the pawl counter-clockwise. The driving part 699 of the coupling 695 is rotatably mounted on a shaft 1| The pawl 694 is connected to a pin 691 having a semi-circular portion (Fig. 28) co-operating with corresponding notches 698 in the driving part 699 of the coupling. This driving part 699 has external teeth engaging a worm pinion 10| mounted on a shaft 102 which is connected through a resilient coupling 103 with a motor 104 (Fig. 30) for driving the machine. On a stub end 105 of the shaft 1|| (Fig. 28) is xed an arm 106 (Fig. 30) connected by a pin 101 to a thrust rod 108. The thrust rod 108 is connected to an arm 1|0 by means of a joint pin 109, which arm ls fixed to the main drive shaft The said shaft also etries a further arm 1|2 (Fig. 30) having a pin A rock lever 1|4 (Fig. 30) is also connected at v688 to the link 681, which lever has a projection 1 5, and at its right hand end bears against a lug 1|6 on the arm 106. The projection 1|5 co-operates with a roller 1|1 attached to a lever 1|9 pivoted at 1|8. The lower end of theflever 1| 9 carries a' contact 126 co-operating with a contact 12| on the machine frame in such a manner that when the two contacts engage the current for` starting the motor 164 is switched on, in a manner not shown. A spring 122 urges the c'ontacts 126, 12| towards each other.

If the shaft 416 is rocked counter-clockwise by means of the lever 414 and rod 462 (Fig. l) to engage the motor drive, the pawl 666 (Fig. 30) releases the square pin 666 and the rod 669 under the action of the spring 618, moves to the left, (Fig. 31) due to the turning of the lever 61|. On counter-clockwise turning of the lever 61| the two armed lever 616, by means of the pin 614, is also turned coimter-clockwiseso that its projection 611 (Fig. 32), releases the arm 616 of the yke 619. By the action of a spring 128 4the yoke 619 is given a counter-clockwise movement which causes the upper'arm 682 of the yoke 619 to. move 4the link 661 to the left in Figs. l30 and 31. The

-link 681 then rocks the lever 696 counter-clockwise whereby thel stop rod 692 is moved to the left (Fig. 29) and the pawl 694 released. By the counter-clockwise movement of the lever '696 the lever 1I4 is moved to the left (Fig. 30) and its projection 1|5 releases the roller 1|1 of the lever 1|9. Under the action of the spring 122 the lever 1I9 can move counter-clockwise to close the z contacts 126, 12|` and start the motor.

Owing to the turning of the pawl 694 in counter-clockwise direction, the semi-circular pin 691 is similarly rotated so that it comes int-o co'operation with one of the notches 698 of the driving member 699 of the coupling, whereby thismember and the driven member`= 695 are coupled. When the motor 164 begins to rotate in counter-clockwise direction due to closure of the contacts 126, 12|, the driving member of the coupling is set in rotation through the elastic coupling-163, shaft '|62 and worm `1I| I. The driven coupling member participates in this rotation due to its connection by means of the .pin 691, and the shaft 1li connected to said member also rotates anti-clockwise. The shaft 1II`, by means of the arm 166 imparts a reciprocatory movement to the connecting rod 108 whereby, through the arm 1I6 the main shaft I. during the rst half of a rotation of the shaft 1||, moves in counter-clockwise direction and during the second half of said rotation,

said main shaft moves in clockwise direction back to the position shown in Fig. 30. The arm 1I! fast on said shaft I (Fig. 30), brings its pin 1|8-into contact with the pawl on the lower arm 66| of the yoke 619 (Fig. 32), during the movement of the main drive shaft in counterclockwise direction. The pawl 684 is thereby turned clockwise against the action of its spring ibut without the-yoke 619 being moved from its coupling engaging position. After the pin 1|! of the arm 1|2 has moved past, the pawl 684 snaps back into the position shown in Fig.

32. At the beginning of the clockwise turning of the main drive shaft I, that is. during the ,second half of a rotation of the shaft 1|I the pin 1I8 ofthe arm 1|2 moves upwardly against the pawl 684 and, as the pawl 84 ca'nnot yield, its further movement shifts the yoke 619 clockwiseback tothe position of Fig. 30. Due to the clockwise movement of the yoke 619, the upperarm 682 causes the link 661 and the stop rod 692 to return to therigbt as in Fig. 29, so hat the rod 692 assumes this right-hand posifion. -After a complete rotation of "the driving member 699 of the coupling thepawi-l strikes also moves to the right so that its projection 1 I5 returns into co-operation with the roller 1|1 of the contact lever 1|9. As long as the shaft 1|I has not completed a full turn, the projection 1|5 and the lever 1I4, due to the action of the spring, moves over the roller 1 i 1 in counterclockwise direction. The motor 164 thus remains switched on during one complete revolution although the lever 1|4 and the projection 1|5 are already in co-operation with the roller 1 I1. Shortly before the shaft 1II has completed a full turn, the right end of the lever 1|4 is engaged by the projection 1|6 on the arm 166 and said lever turned clockwise into the position shown,I in Fig. 30. Clockwise movement of the lever 1I9 thus takes place against the action of the sping 122, opening the contacts 126, 12| and breaking the motor circuit.

'I'he totalizer 3|1 has two seriesl of gear wheels `15u, 15| engaged with each other, Figs. 1v, 1a.

lits rocker arms 151, 158 is mounted loosely on a shaft 16| supported in walls 496, 169 of the machine. The extended pin engages a curved slot 162 in a disc 163. The disc is flxedly mounted on a shaft 164 supported by the side walls 496, 169. The arms 151, '|56 are connected' by a brace 165.

On the counter-clockwise turning of the shaft 164, Fig. 18, the curved slot 162 causes the arms 158, 161 to rock counter-clockwise whereby the gears 15| engage the rack sectors 8. The gears 156, 15| have tens carrying lugs 166, 168 cooperating with carry preparing levers 116, 11|. The levers 116 are supported on a common shaft 112 and the levers 11| on a common shaft 114. The shafts 112, 114 are fixed in the rocker arms 158, 151 and also-serve tobrace said arms. Each carry preparing lever 11| .has an upper extension 115 bearing against the carry preparing lever 116 of the same ordinal places, Fig. 20, and a spring 116 holds the lower arm of the carry preparing lever 11| in contact with the shaft 16|. Arms 111 of the levers 11| bears against fork levers 118 rockably mounted on a common shaft 119` supported by side walls 186, 18|, Fig. 19. These side Walls are fixed on two shafts 182, 866 supported by the side Wallis 496, 169 of the machine. The levers 116 are urged by springs 188 in clockwise direction to hold them against bends 184 of the tens carrying slides 185, Figs. 19, 20, 2l, which slides are 'guided by means of notches in webs 166, 193, slots 181 and pins 188, and a shaft 189, Fig. 2l. The tens carrying slides carry two groups of teeth 196, 19|. Springs 192 urge the slides downwardly, Fig. 21. The gears 156, 15| only engage the slides when the accumulator is disengaged from the rack sectors 3, Fiss. 17, 20, 22.

Each tens carrying slide 185 has an extension which yoke with its shaft 196 is supported in' the sidewalls 180, 18|, and is held by a spring 191 against the extensions 194 0f the slides 185. The yoke 195 has a bend 198 at its left hand end, Fig. 19, co-operating with a lug 199 of the rocker arm 158, Figs. 18, 19. On a shaft 80| is mounted a yoke 802 the left end of which in Figs. 18, 19 has two arms 803, 804 and in the arm 803 is mounted a shaft 806 serving to restore the tens carrying slides 185. Owing to the weight of the shaft 806 the yoke 802 is rocked counter-clockwise to such an extent that the arm 803 bears against the shaft 16|. The arm 804 has a pin 805 co-operating with a heel 801 on the cam disc 163, Fig. 18.

Upon engaging the totalizer 3|1 with the rack sectors 3 from the position shown in Fig, 20 to the position shown in Fig. 21, the carry preparing levers 110, 11| remain in the region of action of the tens carrying lugs 166, 168, Fig. 23, If during setting up of the digits in the numeral wheels of the totalizer 3|1 by means of the rack sectors 3, the value 9 is exceeded in an order, then the tens carrying lug 166, Fig. 23, strikes a nose on the tens carrying lever 110 and rocks said lever in clockwise direction, Fig. 23. The lever 110 carries with it the carry preparing lever 11| bearing against it, which lever 11| rocks in counter-clockwise direction against the action of the spring 116. The arm 111 of the carry preparing lever 11| which bears against the forked lever 118 in both the engaged and disengaged condition of the totalizer 3|1, rotates the forked lever 118 during the rocking of the lever 11|, against the action of the spring 183 and in the clockwise direction Fig. 23. During this rotation of the forked lever 118,- a shoulder 808, Fig. 23, of said lever releases the bend 184 i of the tens carrying slide 185 in the next higher order, so that the corresponding tens carrying slide 185 can move downwardly under the action of its spring 192 until the lug of its extension 194 bears against the yoke 195, Fig. 23, with resulting preparation of the tens carry to be effected. The actual tens carry does not take place until the totalizer 3|1 is disengaged fromthe rack sector 3, and has come into engagement with the tens carrying slide 185, as shown in Fig. 22. On disengagement of the totalizer from the rack sectors 3 and its engagement with the tens carrying slides 185, the lug 199 of the rock lever 158, Figs, 18, 19, 24, encounters the bend 198 of the yoke 195, Fig. 24. Hereby the yoke 195 is shifted against the action of its spring 191, in clockwise direction, Fig. 24, as a result of which all the tens carrying slides 185 are released. Those tens carrying slides 185 which have been prepared for a tens carry by shifting of the forked lever 118 as in Fig. 23, then effect the tens carrying step under the action of their springs 192, such step being limited by the striking of their lower edges on the shaft 806, Fig. 24. Hereby` tens are carried into the next higher orders.

In engaging the totalizer 3| 1 for setting up a further amount during the next machine operation, the heel 801 of the cam disk 163 strikes against the pin 805 on the arm 804 of the yoke 802, Fig 18, imparting to such yoke a rocking movement in counter-clockwise direction, Fig. 24, during which the shaft 806 fixed in the yoke 802 returns the released tens carrying slides 185 from the position of Fig. 24 back into the position of Fig. 20, whereby the tens carrying slides 185 are restored to their normal position and the tens carrying mechanism is ready for further operation.

As shown in Fig. 19, the highest order and the lowest order of the totalizer 3|1 each has a special forked lever 8|0, 8| The forked lever 8|0 of the lowest order and the forked lever 8|| of the highest order are connected to each other by a yoke 8|2. 'I'he forked lever 8|| controls an additional tens carrying slide 8|3 cooperating with gears 8|4, 8|5, Fig. 17, which gears serve to test or determine the sign of the totalizer content as will be hereinafter described, The forked lever 8|0 in the lowest order controls the tens carrying slide 185 which cooperates with the gears of the lowest order. The forked lever 8|0 is moved only by the forked lever 8| and therefore by the tens carrying lugs 166, 168 of the highest order. If the -numeral wheels of the highest order of the totalizer pass through zero then a unit is introduced automatically by means of the yoke 8|2, into the lowest order. This device serves for taking true negative totals. Preferably there is provided in the totalizer 3|1 an additional order and tens carrying device beyond the number of rack sectors and rows of digit /keys 450 that are present, in order that, if the capacity of the totalizer should be exceeded, the sign of its content will remain unchanged and introduction of the fugitive 1 into the lowest order by means of the yoke 8|2 will be prevented,

with actuation of the device hereinafter described for indicating the sign of the totalizer content. The mechanism for introducing the unit into the lowest order operates moreover in practice only when the sign of the totalizerl content changes. The capacity of the orders of the totalizer which are actuated by rack sectors 3, would have to be exceeded ten times before the extra order of the totalizer 3|1, which is not actuated by a rack sector 3, would introduce a fugitive 1 into the lowest order.

As described in the foregoing the totalizer 3|1 is rocked counter-clockwise by means of the cam disk 163 about the axis 16|, Fig. 1c, and thereby engages the rack sector 3. The totalizer 3|1 and the means for conditioning this accumulator for addition or subtraction, are arranged in the same manner as described in the Ewald application Serial No, 39,065, filed September 3, 1935. The right-hand side wall of the frame 156, Fig. 17, carries two pins 322, 323, and the arm 151 carries two pins and 852. On the pins 85| and 852 there is mounted a slide 324 having a. slot 854 in which engage the pins 845|, 852. Washers 855, 856 hold the slide 324 on the pins 85|, 852. The slide 324 has two cam lugs 418, 416 spaced by a gap 900, the pins 322, 323 of the totalizer frame 116 cooperating said lugs and gap.

When the totalizer 3|1 is in the addition position the pin 322 lies against the lug 416 and the pin 323 is in the gap 900. At its lower end the slide 324 has a pin 419,engaging a forked lever 480, Fig. 17, which is fixed by means of a bolt 48|, Fig. 1, to a lever 482. A pin 483 at the upper end of the lever 482 cooperates with a bell-crank 485 pivoted at 484, the right-hand arm ofwhich bell-crank engages a hole 486 in a slide 481, Fig. 18. As shown in Figs. 1 to 5, the slide 481 has slots 488 with-which engage pins 489 carried by brackets 49|, 492, fixed to the side wall 490. The slide 324 has a slot 851, Fig. 17, engaging a pin 858 xed on a slide 339, said slide having a slot 860 engaging a pin 86| on the side wall 169. A shaft 862 is fixed in the side walls 490, 169 and a 

